Islamabad: Elderly adults often experience loss of appetite, resulting in weight loss and under nutrition. Now, researchers suggest this may be down to increased production of a hormone called peptide YY, which tells humans when they are feeling full.

Researchers identified increased production of the “feeling full” hormone PYY in elderly women, which may explain why older adults often experience loss of appetite.

Termed “anorexia of aging,” loss of appetite is common among elderly adults, with around 15-20 percent of seniors experiencing unintentional weight loss as a result.

While loss of appetite in seniors can be driven by emotional issues, such as depression or grief, in many cases, no underlying cause can be found.

Previous research has suggested loss of appetite in the elderly may be down to reduced production of ghrelin – a hormone that tells humans when they are hungry.

However, the new study – conducted by Mary Hickson, professor of dietetics at Plymouth University in the United Kingdom, and colleagues – found the hormone peptide YY may be to blame.

After participants ate, the researchers measured their levels of PYY, ghrelin, and glucagon-like peptide 1 (GLP-1) – a hormone that is responsible for reduced appetite and the release of insulin – at regular time intervals over a 3-hour period.

Additionally, subjects were asked to rate how hungry they were, how much food they thought they would eat, and how pleasant the food was to eat.

Compared with younger adults, the researchers found that adults over the age of 80 demonstrated greater production of PYY. However, there was no difference in ghrelin or GLP-1 levels between the age groups.

What is more, the older adults also reported reduced hunger, reduced prospective food intake, and found the food less pleasant to eat, compared with the younger participants.

Based on their findings, the researchers say it is possible increased production of PYY leads to reduced appetite among elderly adults, causing undernutrition and weight loss.

While further studies are required to assess PYY production in a larger population of older men and women, Prof. Hickson hails the current findings “intriguing.”